Absorbent article and method for its manufacture

ABSTRACT

An absorbent article is provided with a belt  9, 9 ′ attached to or adapted to be attached to the back portion  6  of the article and to the front portion  5  of the article in such a way that the article assumes a pantlike shape, where the belt forms part of the waist portion of the pant and has an outside  11, 11 ′ and an inside  12, 12 ′ which is intended to be in direct contact with a user. The belt comprises first  9  and second  9 ′ belt halves which at one of their ends are permanently attached to the topsheet within bonding areas  13, 13 ′ of the insides  12, 12 ′ in such a way that the belt halves  9, 9 ′ remain substantially flat along their entire length when brought against the topsheet on top of each other, and in such a way that joints  14, 14 ′ which are formed at the bonding areas will be pressed outwards in directions away from the user when the absorbent article is used.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the priority of U.S. Provisional PatentApplication No. 60/290,951, filed May 16, 2001, and Swedish PatentApplication No. 0101731-8, filed on May 16, 2001, the subject matter ofwhich is hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an absorbent article, such as a diaperor an incontinence guard, which is provided with a belt. The inventionfurther relates to a method for manufacturing such an absorbent article.

BACKGROUND OF THE INVENTION

Absorbent articles, such as disposable diapers for infants or adults,are usually provided with a fastening system comprising a pair offastening tabs attached to end portions of the article. As a rule, anabsorbent article is applied to a user who is lying down. The fasteningtabs are intended to engage receiving members located on the other endportion of the article. Such a fastening system is satisfactory when,e.g., diapers are applied to an infant, but problems may arise when anincontinence diaper is to be applied to an adult user, particularly incase the user wants to put the diaper on by himself/herself.

It has been found that absorbent articles provided with a belt,so-called belt diapers, are easier to put on a user who is standing up.Belted absorbent garments are disclosed, for example, in theinternational patent application No. PCT/SE99/01975 and in Swedishpatent No. 514 370.

Furthermore, the international patent application No. WO 99/37263discloses a method and an apparatus for manufacturing belted garments,such as belt diapers, which comprise a first belt half and a second belthalf which both have a longitudinal extension. A carrier web on whichthe first and second belt halves are to be fixed has a first surface anda second surface.

The method according to WO 99/37263 comprises the step of placing thefirst belt half and the second belt half in a partially overlappingrelationship so that a first end region of the first belt half and afirst end region of the second belt half contact each other within aregion of overlap, wherein a second end region of the first belt halfand a second end region of the second belt half remain uncovered. Themethod further comprises the steps of releasably joining the first endregions of the first and second belt halves in order to create atemporary laminate, to bring the first surface of the carrier web andthe temporary laminate in mutual contact so that the first surface ofthe carrier web contacts the laminate in the region of overlap of thefirst end regions of the belt halves, and to get at least a portion ofthe second end region of the first belt half and at least a portion ofthe second end region of the second belt half to contact the secondsurface of the carrier web.

Even if the previously known diapers and absorbent garments providedwith belts have solved some of the above-mentioned problems withdifficult application, there is still room for improvements.

Absorbent articles and garments according to the prior art, forinstance, sometimes may be perceived as uncomfortable by a user,primarily because of the presence of protruding joints and materialedges which are pressed directly against the skin when applying the beltof the article. Where comfort is concerned, it would therefore be amajor advantage to be able to provide an absorbent article or garmenthaving a belt where no such edges pressed inwards against the waist ofthe user will occur beneath the belt when the article has been put on.

Furthermore, the application of belts on absorbent articles during theirproduction has usually been complicated with a large number of differentprocess steps, intermediate laminates, etc. In some cases, this hasresulted in runnability problems and a low production rate. For thisreason, there is a need for a simple and production efficient method forfurnishing an absorbent article or garment with a belt.

SUMMARY OF THE INVENTION

Accordingly, a first object of the present invention is to provide anabsorbent article having a belt which eliminates the above-mentionedproblem with inwardly-protruding joints and material edges which may bepressed against the skin of a user, and which article ensures that theuser can wear the article with the highest possible degree of comfort.

This first object is achieved by means of an absorbent article, such asa diaper or an incontinence guard, which article comprises aliquid-pervious topsheet, a substantially liquid-impermeable backsheetand an absorbent body enclosed therebetween, and which has a frontportion, a back portion and a crotch portion therebetween, and whichfurther is provided with a belt attached to or intended to be attachedto the back portion of the article and to the front portion of thearticle in such a way that the article assumes a pantlike shape wherethe belt forms part of the waist portion of the pant and has an outsideand an inside which is intended to be in direct contact with a user.According to the invention, the belt comprises first and second belthalves which at one of their ends are permanently attached to thetopsheet within bonding areas of the insides in such a way that the belthalves remain substantially flat along their entire length when beingbrought against the topsheet on top of each other, and in such a waythat joints created at the bonding areas will be pressed outwards indirections away from the user when the absorbent article is used.

A second object of the present invention is to provide a simple andproduction efficient method for manufacturing the absorbent articleaccording to the invention.

This second object is achieved by means of a method for manufacturing anabsorbent article, such as a diaper or an incontinence guard, comprisinga liquid-pervious topsheet, a substantially liquid-impermeable backsheetand an absorbent body enclosed therebetween, and which has a frontportion, a back portion and a crotch portion therebetween, and whichfurther is provided with a belt attached to or intended to be attachedto the back portion of the article and to the front portion of thearticle in such a way that the article assumes a pantlike shape wherethe belt forms part of the waist portion of the pant and has an outsideand an inside which is intended to be in direct contact with a user.According to the invention, the method thereby comprises permanentlyattaching first and second belt halves at one of their ends to thetopsheet within bonding areas of the insides in such a way that the belthalves remain substantially flat along their entire length when beingbrought against the topsheet on top of each other, and in such a waythat joints created at the bonding areas will be pressed outwards indirections away from the user when the absorbent article is used.

Further objects of the present invention will become evident from thefollowing description, and the features enabling these further objectsto be achieved are listed in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be described in greater detail withreference to the attached drawings, in which

FIG. 1 schematically and with a cut-away portion shows an absorbentarticle according to a preferred embodiment of the invention,

FIG. 2 schematically illustrates a method according to a first,particularly preferred embodiment of the invention which is intended fortransversal production,

FIG. 3 is section through the upper, longitudinal edge portion of theweb 118 in FIG. 2,

FIG. 4 schematically illustrates a method according to a second,advantageous embodiment of the invention, which also is intended fortransversal production,

FIG. 5 is a section through the upper, longitudinal edge portion of theweb 218 in FIG. 4, and

FIG. 6 schematically illustrates a method according to an alternativeembodiment of the invention, which is intended for longitudinalproduction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 schematically shows an absorbent article according to a preferredembodiment of the invention, more specifically a belt diaper intendedfor adults who suffer from incontinence. However, the invention is notlimited to adult diapers, and absorbent articles or garments accordingto the invention which are intended to be used by young persons orinfants are also conceivable.

The absorbent article 1 comprises a liquid-pervious topsheet 2, asubstantially liquid-impermeable backsheet 3 and an absorbent bodyenclosed therebetween. The liquid-pervious topsheet 2 can consist of anonwoven material, e.g., a spunbond material of continuous filaments, ameltblown material, a bonded carded fiber material, or another soft,flexible and liquid-pervious material. The substantiallyliquid-impermeable backsheet 3 can consist of a plastic film, a nonwovenmaterial coated with a liquid-impermeable material, a hydrophobicnonwoven material, or another flexible material which resists liquidpenetration.

The topsheet 2 and the backsheet 3 have a somewhat larger extension inthe plane than the absorbent body 4 and extend beyond the edges thereof.The layers 2 and 3 are attached to each other within their projectingportions, e.g. by means of gluing or welding by means of heat orultrasonics.

The absorbent body 4 can be of any conventional type. Examples ofcommonly occurring absorption materials are cellulosic fluff pulp,tissue layers, highly absorbent polymers (so-called superabsorbents),absorbent foam materials, absorbent nonwoven materials, and the like. Itis common to combine cellulosic fluff pulp with superabsorbents in anabsorbent body. It is also common with absorbent bodies comprisinglayers of different materials having different properties when liquidacquisition ability, distribution ability, and storage capacity areconcerned. This is well known to the skilled person and will thereforenot be described in detail. The absorbent body is preferably, but notnecessarily, of the relatively thin type which is nowadays common forexample in baby diapers and certain types of incontinence guards, andwhich comprises a compressed, blended or layered structure of cellulosicfluff pulp and superabsorbent.

The diaper 1 is intended to enclose the lower portion of the trunk ofthe wearer as a pair of absorbent pants. It comprises a front portion 5which, during use, is intended to be worn against the front of the bodyof the user, a back portion 6, which during use, is intended to be wornagainst the back of the body of the user, and between the front and backportions a narrower crotch portion 7 which, during use, is intended tobe located in the crotch area between the legs of the user. The frontportion 5 is advantageously provided with a pair of adhesive tape tabsor other suitable fastening members, and preferably with hook members 8belonging to a fastening element of the type which is often referred toas hook-and-loop fastening means or “Velcro” closing.

The article is further provided with a belt 9, 9′ attached to orintended to be attached to the back portion 6 of the article and to thefront portion 5 of the article in such a way that the article assumesthe pantlike shape. Thereby, the belt 9, 9′ will form part of the waistportion of the pant and has an outside 11, 11′ and an inside 12, 12′which is intended to be in direct contact with the user.

In the absorbent article 1 according to the invention, the beltcomprises first 9 and second 9′ belt halves which at one of their endsare permanently attached to the topsheet 2 within bonding areas 13, 13′of the belt insides 12, 12′. According to the invention, the belt halves9, 9′ are attached in such a way that they remain substantially flatalong their entire length when being brought against the topsheet on topof each other, and in such a way that joints 14, 14′ which are createdat the bonding areas will be pressed outwards in directions away fromthe user when the absorbent article is used.

For example, the joint 14′ between the second belt half 9′ and theremaining absorbent article 1 according to the invention will notexhibit any material edge whatsoever during use protruding or extendinginwards towards the waist of the user, and which could be pressedagainst the skin of the user and irritate this. According to thisembodiment, the joint instead will be formed by means of joining twomaterial layers on top of each other at a common end portion, afterwhich the layers are folded away from each other and the joined portionwill assume a “raised” position where the joint 14′ strives outwards andaway from the user. As such, the joint is located at a position outsideof the belt so that an uninterrupted portion of the belt is arrangedbetween the user and the joint, and an inside surface of the belt facesthe user during use of the article. Alternatively, the raised joint isfolded down against one of the material layers and is laid in paralleltherewith, so that a substantially smooth surface facing inwards towardsthe user is obtained. This also applies to the corresponding joint 14 ofthe first belt half 9 or part. Accordingly, the joints 14, 14′ orattachment areas where the belt halves 9, 9′ are attached to thetopsheet 2 of the absorbent article 1 according to the invention willexhibit a very low contact pressure or even no contact at all with theskin of the user. This is rather remarkable, since a conventional beltdiaper would cause a higher contact pressure against the skin of theuser at the belt attachment areas than along the remaining waistband ofthe pantlike shape. The low or nonexistent contact pressure against thewaist of the user which is obtained at the belt attachment areas orjoints 14, 14′ ensures that the user can wear the absorbent article withthe highest possible degree of comfort.

In an alternative embodiment of the absorbent article according to theinvention, pieces of reinforcement material (only shown in FIG. 6) arepermanently attached to opposite edge portions of the topsheet, whereinthe insides of one end of the belt halves within bonding areas areattached to the topsheet via the pieces of reinforcement material. Alsoin this embodiment, no material edges extending inwards and which couldexert a pressure which locally is too high against the skin of the userwill be created at the belt attachment areas. Advantageously, the piecesof reinforcement material comprise an elastic material, something whichgives the user of the absorbent article an improved comfort.

In addition to the fact that the absorbent article gives a very low orno contact pressure against the skin of the user at the attachment areasof the belt halves, the two-parted belt design does not give any risk ofa contact pressure against the skin of the user which is too highoccurring locally against the back of the user. The reason for this isof course that no material edges which could be pressed inwards againstthe back of the user are present, since the belt halves do not continuearound the waist on the back side of the user.

The belt halves 9, 9 can be attached to the topsheet 2 within thebonding areas 13, 13′ by means of any suitable method, by means ofgluing or advantageously by means of thermal bonding with heat, butpreferably by means of thermal bonding with ultrasonics. The belt halvesare with their opposite ends intended to be possible to fasten togetherduring use, e.g., by means of a tape tab, and preferably by means of ahook-and-loop fastening means. Particularly advantageously, a hookmember 15 of a hook-and-loop fastening means can be provided on one ofthe insides 12′ of the belt halves 9′, wherein the outside 11 of theother belt half 9 provides a loop material interacting with the hookmember. Alternatively, a hook member can be provided on the outside ofone of the belt halves, and a loop material on the inside of the otherbelt half.

The above-discussed fastening members 8 or corresponding fasteningmembers on the front portion 5 are intended to be attached against theoutside 11, 11′ of the belt halves 9, 9′ in order to fasten together thediaper into the desired pantlike shape. The fastening members 8preferably are hook members, but can also be of another suitable type.

The belt halves 9, 9′ can consist of any material which is suitable forthe purpose and, for example, can consist of a laminate consisting of anoutside material 11, 11′ forming the outside of the belt and aparticularly soft nonwoven material 12, 12′, which forms the inside ofthe belt and is intended to be in direct contact with the skin of theuser. In such a laminate, the outside material for example can be aplastic film, and the inside material a spunbond material ofpolypropylene or polyethylene with a low bonding degree. In thepreferred embodiment, where the outside material and/or the insidematerial should function as a loop material, the outside and/or theinside of the belt should of course consist of or comprise portions of amaterial which is able to interact with the hook members of thefastening system.

FIGS. 2 and 3 schematically illustrate a method according to a preferredembodiment of the invention which is intended for transversal productionof absorbent articles. In this context, transversal production meansthat the production takes place with the absorbent articles arrangedsidewise in the machine direction of the diaper machine.

The method is intended for manufacturing an absorbent article (see FIG.1), such as a diaper or an incontinence guard, comprising aliquid-pervious topsheet 2, a substantially liquid-impermeable backsheet3 and an absorbent body 4 enclosed therebetween. The absorbent articlehas a front portion 5, a back portion 6 and a crotch portion 7therebetween, and is further provided with a belt 9, 9′ attached to orintended to be attached to the back portion 6 of the article and to thefront portion 5 of the article in such a way that the article assumes apantlike shape, where the belt forms part of the waist portion of thepant and has an outside 11, 11′ and an inside 12, 12′ which is intendedto be in direct contact with a user.

The method comprises permanently attaching first 9 and second 9′ belthalves at one of their ends to said topsheet 2 within bonding areas 13,13′ of said insides 12, 12′ in such a way that the belt halves 9, 9′remain substantially flat along their entire length when being broughtagainst the topsheet on top of each other, and in such a way that joints14, 14′ formed at the bonding areas will be pressed outwards indirections away from said user when the absorbent article is used.

In the preferred embodiment of the method according to the invention,the absorbent article has an article length 116; 216 and an articlewidth 117; 217, and several of the topsheets 102; 202 are provided inthe form of a carrier web 118; 218.

In this manner, a first web 119; 219 is bonded to the carrier web 118;218 within a first bonding area 113; 213 at a first end of the articlewidth 117; 217, whereas a second web 120; 220 displaced by one articlewidth 117; 217 and placed partially on top of the first web 119; 219 isbonded to the carrier web within a second bonding area 113′; 213′ at asecond, opposite end of the article width. Thereafter, the first web andthe carrier web are cut along a first line 121; 221 dividing the firstbonding area 113; 213, whereas the second web and the carrier web arecut along a second fine 122; 222 dividing the second bonding area 113′;213 in order to give the absorbent article the belt 109, 109′; 209,209′.

In a preferred embodiment of the method according to the invention, thefirst 119; 219 and second 120; 220 webs are both shorter than two timesthe article width 117; 217. However, within the scope of the invention,it is conceivable to have embodiments where the first and second webshave a larger length than two times the article width, for example anembodiment where one or both of the free ends of the belt halves aredoubled.

In the preferred embodiment illustrated in FIGS. 2 and 3, the first web119 comprises two of the first belt halves 109, whereas the second web120 comprises two of the second belt halves 109′. Alternatively, thefirst web can comprise two of the second belt halves, and the second webtwo of the first belt halves.

In a second, advantageous embodiment of the method according to theinvention, particularly illustrated in FIGS. 4 and 5, both the first 219and the second 220 webs comprise one of the first belt halves 209 andone of the second belt halves 209′.

FIG. 6 is a schematic illustration of a method according to analternative embodiment of the invention which is intended forlongitudinal production, i.e., the length direction of the absorbentarticles moves in the machine direction of the diaper machine duringproduction.

In the alternative embodiment of the method according to the invention,the absorbent article has an article length 316 and an article width317, and several of the topsheets 302 are provided in the form of acarrier web 318 which is cut along a first line 324 at a first end ofthe article length and along a second fine 325 along a second, oppositeend of the article length.

In the alternative embodiment, pieces of reinforcement material 323,323′ are permanently attached in pairs to opposite edge portions of thecarrier web 318 at an interval corresponding to the article length 316.A first web comprising several of the first belt halves 309 next to eachother and a second web 320 comprising several of the second belt halves309′ next to each other are cut in order to provide one of the first 309and one of the second 309′ belt halves which, before cutting the carrierweb 318, at one of their ends are permanently attached within bondingareas 313, 313′ to the pieces of reinforcement material 323, 323′ inorder to provide the absorbent article with the belt 309, 309′.

In the alternative embodiment, the pieces of reinforcement material 323,323′ preferably are applied to extend outside the article width 317.This facilitates the fitting of an ultrasonic horn or another bondingunit which is to attach the belt ends to the pieces of reinforcementmaterial.

As mentioned above, an elastic material advantageously is utilized inthe pieces of reinforcement material 323, 323′.

In a method according to the invention, preferably the first 119;219;319 and/or second 120; 220; 320 web comprise(s) portions of hookmaterial 115; 215; 315 intended to be included in a hook-and-loopfastening system.

The above-mentioned bonding areas 113, 113′; 213, 213′; 313, 313′ areadvantageously created by means of thermal bonding with heat, orpreferably with ultrasonics, though they can also be created by means ofgluing.

In a method according to the invention, preferably two belt halves aresimultaneously permanently attached to the carrier web 118; 218; 318,either directly or via the pieces of reinforcement material 323, 323′.This reduces the number of process stages and results in more efficientproduction.

As evident from the foregoing, the method according to the invention canbe performed by means of a diaper machine or corresponding machine fortransversal production or, alternatively, by means of a machine forlongitudinal production. Such machines are commercially available, andit should not pose any difficulties to the skilled person havingknowledge about the present invention to adapt such a machine in orderto be able to implement the invention. Accordingly, it is not necessaryto describe the basic technique and necessary equipment formanufacturing diapers herein.

In the foregoing, the present invention has been described by means ofseveral embodiments and with reference to the attached drawings.However, the invention is by no means restricted to the specificembodiments which have been described above or shown in the drawings;instead the scope of the invention is defined by the following claimsand equivalents thereof.

1-6. (canceled)
 7. A method for manufacturing an absorbent articlecomprising a liquid-pervious topsheet, a substantiallyliquid-impermeable backsheet and an absorbent body enclosedtherebetween, said article having a front portion, a back portion and acrotch portion therebetween, and further being provided with a beltattached to or adapted to be attached to the back portion of the articleand to the front portion of the article, in such a way that the articleassumes a pant shape where the belt forms part of the waist portion ofthe pant and has an outside and an inside which is intended to be indirect contact with a user, the method comprises permanently attachingan inside of first and second belt halves at ends of the belt halves tosaid topsheet within bonding areas in such a way that said belt halvesremain substantially flat along their entire length when brought againstsaid topsheet on top of each other, and each of the belt halves has anuninterrupted portion extending from the respective bonding area in sucha way that joints formed at said bonding areas will be at a positionoutside of the uninterrupted portion of the belt away from the user whenthe absorbent article is used.
 8. The method according to claim 7,wherein said absorbent article has an article length and an articlewidth, and several of said topsheets are provided in the form of acarrier web, wherein a first web is bonded to said carrier web within afirst bonding area at a first end of said article width, and that asecond web displaced by one article width and placed partially on top ofsaid first web is bonded to said carrier web within a second bondingarea at a second, opposite end of said article width, whereafter saidfirst web and said carrier web are cut along a first line dividing thefirst bonding area, whereas said second web and said carrier web are cutalong a second line dividing said second bonding area in order toprovide the absorbent article with said belt.
 9. The method according toclaim 8, wherein said first and second webs are both shorter than twotimes the article width.
 10. The method according to claim 8, whereinthe first web comprises two of said first belt halves, and that thesecond web comprises two of said second belt halves.
 11. The methodaccording to claim 8, wherein the first web comprises two of said secondbelt halves, and that the second web comprises two of said first belthalves.
 12. The method according to claim 8, wherein said first andsecond webs both comprise one of said first belt halves and one of saidsecond belt halves.
 13. The method according to claim 7, wherein themethod is performed by means of a diaper machine or correspondingmachine for transversal production.
 14. The method according to claim 7,wherein said absorbent article has an article length and an articlewidth, and several of said topsheets are provided in the form of acarrier web which is cut along a first line at a first end of saidarticle length and along a second line at a second, opposite end of saidarticle length wherein pieces of reinforcement material are permanentlyattached in pairs to opposite edge portions of said carrier web at aninterval comprising said article length, and that a first web comprisingseveral of said first belt halves next to each other and a second webcomprising several of said second belt halves next to each other are cutin order to provide one of said first and one of said second belthalves, which, before cutting the carrier web, at one of their ends arepermanently attached within bonding areas to said pieces ofreinforcement material in order to provide the absorbent article withsaid belt.
 15. The method according to claim 14, wherein the pieces ofreinforcement material are applied to extend outside said article width.16. The method according to claim 14, wherein an elastic material isutilised in said pieces of reinforcement material.
 17. The methodaccording to claim 14, wherein the method is performed by means of adiaper machine or corresponding machine for longitudinal production. 18.The method according to claim 7, wherein said first and/or said secondweb comprise(s) portions of hook material intended to be included in ahook-and-loop fastening means.
 19. The method according to claim 7,wherein said bonding areas are created by means of thermal bonding withheat or ultrasonics.
 20. The method according to claim 7, wherein saidbonding areas are created by means of gluing.
 21. The method accordingto claim 7, wherein two belt halves are simultaneously permanentlyattached to the carrier web.
 22. The method of claim 7, wherein theabsorbent article is a diaper or an incontinence article.